All e⁻s, protons & neutrons are concentrated in very small center part, nucleus. On applying high voltage btw 2 metal plates at ends of glass tube, invisible
cathode ray is produced, moving from cathode to anode in straight line.
e⁻s are revolving around nucleus in circular paths, orbits.
Postulates Cathode Tube is filled with gas (eg. H₂) at low pressure, around 10⁻² mm Hg.
As e⁻ revolves in circular orbits, its energy stays constant, neither losing nor gaining, aka 'stationary orbit'. E ∝ orbit no of Bohr Ray Exp:
Theory JJ Thomson (1897) found that e/m (charge/mass) ratio is constant at 1.76
Discovery
E⁻s orbit the nucleus in circular paths with angular momentum being whole no. Angular x 10^8 Cg⁻¹ regardless of type of tube or metal in electrodes or gas used.
of e-(JJ
multiples of h/2π. mvr = n h/2π Momentum Thomson)
Quantization of e- They can ionise atom of filled gas
n=1,2,3...; m= mass of e-; v= velocity of e-; r= radius of orbit; mvr= angular momentum
Anode rays are produced due to ionisation of gaseous atoms
Radiations of every wavelength are present in continuity Continuous Spectrum
in a tube, as a result of collision with accelerated e⁻s.
Anode/ Canal Ray
All continuous wavelengths are present except those absorbed by atoms Exp (Goldstein)
Discontinuous +ve charged particle in canal ray isn't exactly proton. Its
In case of 'Na' we get black line in yellow range spectrum mass & e/m ratio vary with change in gas, suggesting,
but in 'K' we get black line in Violet range every atom consists of +vely charged particle, proton.
Types of
Record of those EMRs which are emitted by a substance or any source. Emission spectrum Electromagnetic Travel in a straight line (produce sharp
Spectrum shadow of solid object placed in path)
Record of those EMRs which are absorbed by a substance Absorption spectrum
Characteristics Show particle nature (it can rotate small pin wheel placed in path)
Emission spectrum of simple atom like 'H' has some limited no. of Line
of cathode/
lines. Each line is corresponding to 1 transition. spectrum Consist of -ive(CR)/+ve(AR) charged particles (⊥ EF
anode ray
deflects them to anode(CR) /cathode(AR))
Molecules have many lines in their emission spectrum, organized in groups (bands) Band spectrum
⊥ MF deflects them to south(CR) /north pole(AR)
A black body can emit or absorb radiation across all frequencies or wavelengths, aka black body radiation. Black Body
Sequence of EMRs in decreasing frequency or increasing wavelength is EMS. Discovery On colliding of high voltage α-particle with 'Be' atom, new element 'C'
Electromagnetic of Neutron & new undeflected particle, neutron is ejected suggesting it's neutral
λ= 380 nm \VIBGYOR/ λ= 760nm
γ-Ray | X-Ray | UV | Visible | IR | Microwave | Radio wave
Spectrum (EMS) Structure of Atom
Most of α-particle passed through gold foil- undeflected (99.9%)
------------------------------------------------------> Obs. of Rutherford
Decreasing ʋ & Energy of 1 quanta ; Increasing λ α-particle Few α-particles(0.1%) passed through gold foil- deflected at small angles
Scattering Exp.
Any body can emit or absorb energy discontinuously in form of small packets of energy called quantum [quanta]. Only 1 α-particle out of 20000, deflects back through gold foil
Energy of 1 quantum is directly proportional to frequency of EMR Protons(+ve charged) are conc'ted in very small center, nucleus
Planck's
E= energy of 1 quanta; E∝ʋ Quantum All mass of atom is conc'ted in nucleus
Postulate of
ʋ= frequency of EMR; => E = hʋ Theory
Rutherford e- are moving around nucleus in circular path, orbit
h= Planck's constant= 6.626 Js = hc/λ
Str. of atom
e- are moving around nucleus under electrostatic attrac'n force
Total energy from a monochromatic light source is a multiple of 1 quantum's energy. ET= nE
Radius of atom : 10⁻⁸ cm
Can travel in vacuum, doesn't require any medium Radius of nucleus: 10⁻¹³ cm
Constant velocity always, i.e. 3×10⁸ m/s
Limitations of Can't explain stability of atom
Dist'n btw center point of 2 neighboring crest or trough Rutherford Model
Wavelength (λ) No info about distribution of e- in different orbits
1 m = 10² cm= 10³ mm= 10⁶μm = 10⁹nm= 10¹⁰ A°=10¹² pm λ∝1/ʋ
Characteristics
λ=ϲ/ʋ An accelerating charged particle produces oscillating MF
No. of cycle of radiation passing through a point in 1 sec. Unit: Hz, cycle s⁻¹ Frequency (ʋ) of EMR Electromagnetic
& EF mutually perpendicular to each other & direction
Radiation (EMR)
of radiation, both travelling in form of wave (disturbance)
Max'm ↑ward or ↓ward displacement from center Amplitude (a)
No of cycle present in distance of 1 cm, v¯= 1/λ(cm); unit: cm⁻¹ Wave No.(v¯)
Time required to complete 1 cycle, unit: Hz⁻¹, s/cycle; T=1/ʋ Time Period (T)
cathode ray is produced, moving from cathode to anode in straight line.
e⁻s are revolving around nucleus in circular paths, orbits.
Postulates Cathode Tube is filled with gas (eg. H₂) at low pressure, around 10⁻² mm Hg.
As e⁻ revolves in circular orbits, its energy stays constant, neither losing nor gaining, aka 'stationary orbit'. E ∝ orbit no of Bohr Ray Exp:
Theory JJ Thomson (1897) found that e/m (charge/mass) ratio is constant at 1.76
Discovery
E⁻s orbit the nucleus in circular paths with angular momentum being whole no. Angular x 10^8 Cg⁻¹ regardless of type of tube or metal in electrodes or gas used.
of e-(JJ
multiples of h/2π. mvr = n h/2π Momentum Thomson)
Quantization of e- They can ionise atom of filled gas
n=1,2,3...; m= mass of e-; v= velocity of e-; r= radius of orbit; mvr= angular momentum
Anode rays are produced due to ionisation of gaseous atoms
Radiations of every wavelength are present in continuity Continuous Spectrum
in a tube, as a result of collision with accelerated e⁻s.
Anode/ Canal Ray
All continuous wavelengths are present except those absorbed by atoms Exp (Goldstein)
Discontinuous +ve charged particle in canal ray isn't exactly proton. Its
In case of 'Na' we get black line in yellow range spectrum mass & e/m ratio vary with change in gas, suggesting,
but in 'K' we get black line in Violet range every atom consists of +vely charged particle, proton.
Types of
Record of those EMRs which are emitted by a substance or any source. Emission spectrum Electromagnetic Travel in a straight line (produce sharp
Spectrum shadow of solid object placed in path)
Record of those EMRs which are absorbed by a substance Absorption spectrum
Characteristics Show particle nature (it can rotate small pin wheel placed in path)
Emission spectrum of simple atom like 'H' has some limited no. of Line
of cathode/
lines. Each line is corresponding to 1 transition. spectrum Consist of -ive(CR)/+ve(AR) charged particles (⊥ EF
anode ray
deflects them to anode(CR) /cathode(AR))
Molecules have many lines in their emission spectrum, organized in groups (bands) Band spectrum
⊥ MF deflects them to south(CR) /north pole(AR)
A black body can emit or absorb radiation across all frequencies or wavelengths, aka black body radiation. Black Body
Sequence of EMRs in decreasing frequency or increasing wavelength is EMS. Discovery On colliding of high voltage α-particle with 'Be' atom, new element 'C'
Electromagnetic of Neutron & new undeflected particle, neutron is ejected suggesting it's neutral
λ= 380 nm \VIBGYOR/ λ= 760nm
γ-Ray | X-Ray | UV | Visible | IR | Microwave | Radio wave
Spectrum (EMS) Structure of Atom
Most of α-particle passed through gold foil- undeflected (99.9%)
------------------------------------------------------> Obs. of Rutherford
Decreasing ʋ & Energy of 1 quanta ; Increasing λ α-particle Few α-particles(0.1%) passed through gold foil- deflected at small angles
Scattering Exp.
Any body can emit or absorb energy discontinuously in form of small packets of energy called quantum [quanta]. Only 1 α-particle out of 20000, deflects back through gold foil
Energy of 1 quantum is directly proportional to frequency of EMR Protons(+ve charged) are conc'ted in very small center, nucleus
Planck's
E= energy of 1 quanta; E∝ʋ Quantum All mass of atom is conc'ted in nucleus
Postulate of
ʋ= frequency of EMR; => E = hʋ Theory
Rutherford e- are moving around nucleus in circular path, orbit
h= Planck's constant= 6.626 Js = hc/λ
Str. of atom
e- are moving around nucleus under electrostatic attrac'n force
Total energy from a monochromatic light source is a multiple of 1 quantum's energy. ET= nE
Radius of atom : 10⁻⁸ cm
Can travel in vacuum, doesn't require any medium Radius of nucleus: 10⁻¹³ cm
Constant velocity always, i.e. 3×10⁸ m/s
Limitations of Can't explain stability of atom
Dist'n btw center point of 2 neighboring crest or trough Rutherford Model
Wavelength (λ) No info about distribution of e- in different orbits
1 m = 10² cm= 10³ mm= 10⁶μm = 10⁹nm= 10¹⁰ A°=10¹² pm λ∝1/ʋ
Characteristics
λ=ϲ/ʋ An accelerating charged particle produces oscillating MF
No. of cycle of radiation passing through a point in 1 sec. Unit: Hz, cycle s⁻¹ Frequency (ʋ) of EMR Electromagnetic
& EF mutually perpendicular to each other & direction
Radiation (EMR)
of radiation, both travelling in form of wave (disturbance)
Max'm ↑ward or ↓ward displacement from center Amplitude (a)
No of cycle present in distance of 1 cm, v¯= 1/λ(cm); unit: cm⁻¹ Wave No.(v¯)
Time required to complete 1 cycle, unit: Hz⁻¹, s/cycle; T=1/ʋ Time Period (T)
